As a gas turbine engine operates, airborne contaminants may coat the blades and the vanes of the compressor and other components. Over time, particulate accumulation may restrict the airflow through the compressor and may adversely impact on the overall gas turbine engine performance and efficiency. In order to reduce such accumulation, water wash systems may be used to remove the accumulated particulate matter from the compressor blades and vanes.
Although such water wash systems may be effective in cleaning early compressor stages, the middle and later compressor stages often show reduced cleaning or relatively little cleaning at all. Specifically, the cleaning solution is generally injected about a bellmouth at the front end of the compressor. The cleaning solution may be degraded or vaporized by the time the later stages are reached. Moreover, the nozzles for the cleaning solution may become plugged so as to reduce further the cleaning effectiveness as well as producing undesirable variations in the spray patterns. Other known methods for cleaning compressors include increasing the duration and/or frequency of the washes, increasing the ratio of the cleaning solution to water, changing the type of cleaning solution, use of foam-based cleaning agents, and/or performing periodic manual cleaning.
There is thus a desire for improved offline compressor wash systems and methods. Preferably, such improved systems and methods may adequately wash all of the compressor stages, particularly the later compressor stages, so as to provide improved performance and efficiency.